This invention addresses the problem of inadequate illumination in hospital rooms that may lead to general confusion and delirium. It proposes and describes a system that supports temporal and spatial orientation by rendering lighting scenes that mimics the dynamics of a skylight window. Patients subject to the proposed illumination are expected to be better oriented in terms of time flow and room orientation. Although the system will mainly benefit patients in spaces that lack adequate windows, the possibility of rendering lighting conditions that resemble sunny ‘upbeat’ days will also benefit a broader range of patients during dark winters and gloomy rainy days.
The inventor of the present invention has appreciated that a system and method according to the present invention for providing light to a room, especially an intensive care unit, will reduce the risk of delirium of a patient and has in consequence devised the present invention.
Delirium is an etiologically nonspecific organic cerebral syndrome characterized by concurrent disturbances of consciousness and attention, perception, thinking, memory, psychomotor behavior, emotion, and the sleep-wake schedule. The incidence of delirium among ICU patients has been reported to be high despite great variation in the statistics (20-80%).
The negative impact of ICU delirium can be felt in several spheres. Economically, delirium has been consistently linked to greater healthcare expenditures due to longer hospitalization periods. Furthermore, patients who develop delirium are more likely to die or suffer complications on the short or medium term as delirium has been shown to shown to be a good predictor of long-term cognitive impairment among ICU patients. In the social sphere, staff morale is affected because of reduced job satisfaction experienced when dealing with agitated and non-compliant patients.
As a state of cognitive confusion all preventive and intervention measures against delirium have the primary objective of re-orienting patients. Non-pharmacological approaches that complement the use of drugs with dangerous side-effects generally include the correction of sensory deficiencies (e.g. eyeglasses and hearing aids) for supporting patient orientation and minimizing misperceptions of objects in the environment as well as periodic cognitive stimulation and verbal reorientation.
In this regard, lighting conditions are known to greatly influence temporal and spatial orientation of humans. Throughout the day, the sky color and the intensity of the illumination provided by the sun varies. Shadows are constantly moving, changing length and direction. Such dynamics provide intuitive ways on which humans rely to measure passage of time or locating cardinal points. Unfortunately, this information is largely lost in indoor environments and in particular hospital rooms in which patients do not have the benefit of appropriate external lighting conditions via windows.
In a study conducted by Keep et al. (Windows in the intensive therapy unit. Keep, P., James, J. and Inman, M. 3, 1980, Anaesthesia, Vol. 35, pp. 257-262) the authors observed that patients who had survived a stay of at least 48 h in an ICU had a less accurate memory of the length of their stay, and were less well orientated in time if the unit was windowless. Furthermore, the authors reported that the incidence of hallucinations and delusions was more than twice as high in the windowless unit when compared to a similar unit with translucent but not transparent windows.